The invention relates to an apparatus for the continuous bonding and/or welding of material webs using ultrasound, having an ultrasonic horn configured as a rotating roller, an anvil disposed radially opposite the rotating roller, an amplitude transformer set axially on the rotating roller, and an ultrasonic converter with an energy supply attached to the amplitude transformer.
It is known that for the continuous welding and/or bonding of material webs. The material webs are passed through a rotating roller and a fixed or similarly rotating roller and thereby processed. With fixed ultrasonic horns, large material widths can be covered, but a frictional force arises between the ultrasonic horn and the moving material web, negatively affecting the welding result. In addition, the frictional force causes heating of both the material webs and of the ultrasonic horn, thereby changing the pre-set gap.
The above described disadvantage of friction can be prevented with rotating ultrasonic horns, but only narrow-width welds can be performed. From U.S. published application 2002/030157, an ultrasonic horn is known with a width that is smaller than lambda-half. This also applies to the devices known from U.S. Pat. Nos. 5,707,483 and U.S. 6,547,903.